Answer and Explanation:
This quote means that the person is able to handle bad things thrown in their way and still be good or mildly unaffected.
Non-metaphorically, this quote is saying that the sea us unaffected or isn't changed when a stream that is polluted runs into this sea.
Metaphorically, the quote is saying that the person is the sea, in which small things, like the river, won't affect the entirety of them.
#teamtrees #PAW (Plant And Water)
I hope this helps!